CA Pub Util Code Section 132301

A retail transactions and use tax ordinance applicable in the incorporated and unincorporated territory of the county shall be imposed by the commission in accordance with Section 132307 and Part 1.6 (commencing with Section 7251) of Division 2 of the Revenue and Taxation Code, if two-thirds of the electors voting on the measure vote to approve its imposition at a special election called for that purpose by the commission. The tax ordinance shall take effect at the close of the polls on the day of election at which the proposition is adopted. The initial collection of the transactions and use tax shall take place in accordance with Section 132304. If, at any time, the voters do not approve the imposition of the transactions and use tax, this chapter remains in full force and effect. The commission may, at any time thereafter, submit the same, or a different, measure to the voters in accordance with this chapter.